Vacuum pumps can be used in a number of different operations. In some instances, vacuum pumps can be designed to be used on air conditioners and will still function even when containing ferrous metal parts. However, when they are used in the application of a freeze dryer, rust contaminates the system and thereby creates problems in the operation. For example, after use, the vacuum pump becomes full of rust water and particulate. In order to keep the system operational after normal use, the system needs to be cleaned and re-lubricated with large amounts oil, which require hours to accomplish.
Previous attempts have tried to solve this problem in the past by using a vacuum pump's motor to move oil through a 7 micron car oil filter at a rate of six cubic feet of oil per minute. However, the pump's reservoir creates an extremely high amount of pressure. The high pressure leads to problems and several mishaps have occurred, which include sight glasses blowing out and the covers of the reservoirs rupturing.
Additionally, several designs were created as an attempt to filter contaminated oil. Some designs attempted to filter the contaminated oil by circulating the oil from the vacuum pump's drain through a filter and back into the oil fill, which necessitates using additional pumps and filters. But these designs failed to adequately clean the oil and the internal parts of the pump. Thus, there is a long felt need in solving the aforementioned problems.